Eritrea is the world’s worst country for press censorship, a media watchdog said Tuesday in a report which also cites extreme measures in nine other countries including North Korea, China and Saudi Arabia.

Under the three worst regimes — Eritrea, North Korea, and Turkmenistan — the media “serves as a mouthpiece of the state, and any independent journalism is conducted from exile,” said a report by the US-based Committee to Protect Journalists.

Other countries on the list of the 10 worst regimes for media “use a combination of blunt tactics like harassment and arbitrary detention as well as sophisticated surveillance and targeted hacking to silence the independent press,” the report said.

Saudi Arabia, China, Vietnam, and Iran were cited for “jailing and harassing journalists and their families, while also engaging in digital monitoring and censorship of the internet and social media,” the group said.

The rankings were based on factors including restrictions on privately owned or independent media; criminal defamation laws; restrictions on the dissemination of false news; blocking of websites; surveillance of journalists by authorities; license requirements for media; and targeted hacking or trolling.

“The internet was supposed to make censorship obsolete, but that hasn’t happened,” said CPJ executive director Joel Simon.

“Many of the world’s most censored countries are highly wired, with active online communities. These governments combine old-style brutality with new technology, often purchased from Western companies, to stifle dissent and control the media.”

The report covers 10 countries where the government tightly controls the media, including Equatorial Guinea, Belarus, and Cuba.

It noted that in other countries including war-ravaged nations such as Syria, Yemen, and Somalia, conditions for the media are “extremely difficult, but not necessarily attributable solely to government censorship.”

In Eritrea, the report noted, the state retains a legal monopoly of broadcast media and journalists’ alternative sources of information, such as the internet or satellite broadcasts of radio stations in exile, are restricted via government-controlled internet services.

North Korean leader Kim Jong Un has stepped up the use of radio signal blockers and advanced radio detection equipment to prevent people from sharing information, CPJ said.

The group said Saudi Arabia’s already-repressive environment for the press has “suffered sharp deterioration” under de facto ruler Crown Prince Mohammed bin Salman, according to the report.

China has the most sophisticated censorship apparatus, according to CPJ, which noted that Chinese internet users are blocked by the “Great Firewall” and that authorities monitor domestic social media networks and conduct surveillance of international journalists.